One of the hazards of driving motor vehicles such as automobiles, trucks and buses is that of accidentally falling asleep. The problem is particularly serious for over the road trucks and others who must drive long distances on interstate highways at all hours of the day and night. The problem is exacerbated by boring stretches where there is little or nothing of interest and a driver rivets his/her eyes on the road for hour after hour without a break
A type of sleep attributed to driving and particularly long-distance driving is not the deep sleep of normal rest, but rather a form of auto hypnosis which has been defined as a state of intense reverie. It can result from prolonged fixation of sight or boredom or fixation of attention on a single relatively monogamous subject such as the hum of tire treads or sound of the motor. A tendency to doze off during such periods is often intensified by fatigue or lack of sleep.
Whatever the problem, a tendency to doze off while operating a motor vehicle can lead to a tragic result for a driver and/or innocent third parties. For this reason, there have been numerous approaches to provide an alarm that can be utilized by the driver to inhibit sleeping while at the wheel of the motor vehicle.
For example, a U.S. Pat. No. 2,711,528 of Glossbrenner, discloses a relatively simple waking alarm for vehicle operators. The patent discloses a light weight device comprising a first electrical contact supported in a motor vehicle in spaced relation to the head of the operator. The contact is connected to a circuit of an electrically actuated horn. A second electrical contact member is carried by the drivers head. Then, when the drivers head is moved out of its normal position or range of normal positions, the first contact engages the second contact member to sound the vehicle's horn and awaken the driver.
A more recent approach to a sleep preventing device is disclosed in the U.S. Pat. No. 3,045,225 of Baldwin. As disclosed therein, a noise making device automatically sounds a warning when the head of a user nods forwardly. Another approach to a drowsiness detecting apparatus is disclosed in the U.S. Pat. No. 4,144,531 of Anbergen. Anbergen discloses an apparatus for detecting an individual becoming drowsy that includes a wave emitter mounted on an eyeglass frame for emitting a wave along a path directed to pass close to an individual's eyeball without impinging on the eyeball. However, the wave is interrupted by the eyelashes when the eyelid is moving. A detector is disposed on the frame and signaling means are provided to produce an alarm signal at a predetermined time after the last eyelid movement.
Another warning system for warning a user that they have fallen or are about to fall asleep is disclosed in the U.S. Pat. No. 6,087,941 of Ferroz. The system includes a contact lens having a detectable feature such as a hologram or other markings or indicia, metallic substances, color or micro-circuit device which will be worn by the user. The system also includes a detector that detects the presence of the contact lens when the eyelids of the person wearing the contact lens are open. When the eyelids of the user become heavy or closed so as to cover a substantial portion of the detectable feature of the contact lens for a predetermined period, the detector generates a signal to waken the user.
Notwithstanding the above, it is presently believed that there may be a large commercial market for a warning device in accordance with the present invention. There should be a demand for such devices because they are relatively economical to manufacture, relatively durable in use and reliable. Further, such devices enable an individual to use an audible or tactile warning as well as a warning for the driver alone and/or a warning to alert passengers of a potential problem.